System and methods for adaptive equalization for optical modulation formats

摘要

A method for modifying the performance of an adaptive equalizer in a receiver is provided. A carrier wave comprising a first polarization state and a second polarization state, wherein there is a correlation between the first polarization state and the second polarization state, is received. The first polarization state and the second polarization state are demultiplexed to generate two respective constellations. A first expected value based on the first constellation, and a second expected value based on the second constellation, are calculated. An adaptive equalizer receives a first and second signals associated with the respective polarization states. The adaptive equalizer generates outputs based on the signals. These outputs are used to generate error values. Feedback is input into the adaptive equalizer, wherein the feedback is based on the error values.

主权项

1. A method, comprising:
receiving a carrier wave comprising a first polarization state and a second polarization state, wherein a correlation exists between the first polarization state and the second polarization state; generating a first constellation corresponding to the first polarization state and a second constellation corresponding to the second polarization state; calculating a first expected value based on the first constellation and a second expected value based on the second constellation; equalizing, by an adaptive equalizer, a first output based on a first signal associated with the first polarization state and a second output based on a second signal associated with the second polarization state; calculating a first error based on a difference between the first expected value and the first output, the first expected value being constrained based on the first output and the second output; calculating a second error based on a difference between the second expected value and the second output, the second expected value being constrained based on the first output and the second output; generating a feedback signal based on the first error, the second error and the correlation; and determining coefficients for filters of the adaptive equalizer using the feedback signal.